--- ray/src/rt/m_brdf.c	1993/05/27 15:28:01	2.6
+++ ray/src/rt/m_brdf.c	1994/01/12 16:46:35	2.10
@@ -21,7 +21,8 @@ static char SCCSid[] = "$SunId$ LBL";
  *  String arguments include the reflection function and files.
  *  The BRDF is currently used just for the specular component to light
  *  sources.  Reflectance values or data coordinates are functions
- *  of the direction to the light source.
+ *  of the direction to the light source.  (Data modification functions
+ *  are passed the source direction as args 2-4.)
  *	We orient the surface towards the incoming ray, so a single
  *  surface can be used to represent an infinitely thin object.
  *
@@ -88,6 +89,7 @@ double  omega;			/* light source size */
 	COLOR  ctmp;
 	FVECT  ldx;
 	double  lddx[3], pt[MAXDIM];
+	double  vldx[4];
 	register char	**sa;
 	register int	i;
 
@@ -153,8 +155,9 @@ double  omega;			/* light source size */
 	} else {
 		for (i = 0; i < np->dp->nd; i++)
 			pt[i] = funvalue(sa[3+i], 3, lddx);
-		dtmp = datavalue(np->dp, pt);
-		dtmp = funvalue(sa[0], 1, &dtmp);
+		vldx[0] = datavalue(np->dp, pt);
+		vldx[1] = lddx[0]; vldx[2] = lddx[1]; vldx[3] = lddx[2];
+		dtmp = funvalue(sa[0], 4, vldx);
 		setcolor(ctmp, dtmp, dtmp, dtmp);
 	}
 	if (errno) {
@@ -194,7 +197,6 @@ register RAY  *r;
 	double  transtest, transdist;
 	int  hasrefl, hastrans;
 	COLOR  ctmp;
-	double  dtmp;
 	register MFUNC  *mf;
 	register int  i;
 						/* check arguments */
@@ -239,6 +241,7 @@ register RAY  *r;
 						/* compute transmitted ray */
 	setbrdfunc(&nd);
 	transtest = 0;
+	transdist = r->rot;
 	errno = 0;
 	setcolor(ctmp, evalue(mf->ep[3]),
 			evalue(mf->ep[4]),
@@ -265,7 +268,7 @@ register RAY  *r;
 		transdist = r->rot + sr.rt;
 	}
 	if (r->crtype & SHADOW)			/* the rest is shadow */
-		return;
+		return(1);
 						/* compute reflected ray */
 	setbrdfunc(&nd);
 	errno = 0;
@@ -305,6 +308,8 @@ register RAY  *r;
 						/* check distance */
 	if (transtest > bright(r->rcol))
 		r->rt = transdist;
+
+	return(1);
 }
 
 
@@ -318,7 +323,7 @@ register RAY  *r;
 	double  dtmp;
 						/* always a shadow */
 	if (r->crtype & SHADOW)
-		return;
+		return(1);
 						/* check arguments */
 	if (m->oargs.nsargs < (hasdata(m->otype)?4:2) | m->oargs.nfargs <
 			(m->otype==MAT_TFUNC|m->otype==MAT_TDATA?6:4))
@@ -378,6 +383,8 @@ register RAY  *r;
 	}
 						/* add direct component */
 	direct(r, dirbrdf, &nd);
+
+	return(1);
 }